Engine/Transmission (1994 - 1998) AFC cover position???

[BrosseauJD]

Hello,



I have recently installed a TST #8 plate in my truck. I have been "messing" :-laf with the position of the plate, AFC star wheel, and housing cover position. I was wondering if someone could give me an explanation of the relationship to each other, and each parts actual purpose. I understand the plate to be a full movement stop. Does this mean the plate only affects full throttle? I have adjusted the star wheel to its fullest extent forward. I know the AFC cover is sensing boost pressure, and therefore richening the fuel. My question for the cover is, forward or backward???? The TST instructions recommend all the way back... . but they also say put the new plate in exactly the same position as the stock! Does the arm move forward when boost pressure is applied to the internal diaphragm; and is this what contacts the new TST Plate? The truck doesn't seem any different with the plate and wheel fully forward. The smoke is still very minimal, and the gains are not noticeable.



Thank you very much for reading my rambling, any info would be appreciated!

 

[Neibe]

If I'm not mistaken the cover has to be full forward.

 

[Neibe]

Yeah I just went on their website and it says to slid the cover as far forward as the slot will allow. Also, make sure all screws are tight I had the cover loosen up on me it made an oil mess and I lost power. If you slid the cover forward towards front of the engine you'll notice the difference. What boost numbers are you getting? Did you turn the star wheel towards the engine? It should smoke like a freight train.

 

[BrosseauJD]

I have tried the cover in both positions forward and back. My boost went from the standard 18 PSI at WOT to over 35PSI in both positions (It pegs my 35PSI gauge, so I don't know exactly how high it is going). I turned the top of the AFC wheel towards the engine, which moved the adjuster towards the front of the engine. I actually have it as far forward as it will go. I get some smoke when I first mash the gas, but after a second or less it goes away. My Exhaust gas has not exceeded 1200 no matter how it has been set up.



PS. I don't pull a very heavy trailer. The trailer is only about 5500lbs. Maybe the truck just isn't calling for that much power?

 

[pwerwagn]

Your AFC's purpose is to limit off-boost and low boost power. The "foot" essentially acts as the plate under low boost conditions. The spring is what keeps the foot in front of the plate. The rate of your spring determines a lot. how tight the starwheel is and the position of the cover, are the main easy adjustments to make. for example, if you have a 20in lb spring (just makin a number up here), it will take 20 psi to move the spring one inch. so if the foot is one inch foward of the plate (again, an arbitrary #), it will take 20 psi to make the foot move out of the way from the plate. then the plate comes into play. You can also adjust the initial position of the foot in the housing. There is a cover on the back of the housing (towards the firewall) that has an allen adjustment. there is also an adjustment on the front of the housing that adjusts the "height" of the foot in the housing.

So, if you move the afc foward and loosen the spring, your gov lever will contact the plate sooner, but your smoke level will be greater. Play with the adjustments to get the desired effect.

FYI, i moved my foot foward 2 full turns (the back adjustment), I have the cover full foward, and I have the starwheel about 6 clicks from being loose.

--Jeff

 

[JAmos]

I have mine full forward and the star wheel all the way forward(backed off). Works good for me so far. How is an afc gutted? What is left inside? In a thread I started a while ago I think it was Forrest Nearing who said that a lot more smoke was possible, so have been wanting to gut my afc.



Jordan

 

[pwerwagn]

You can take the foot out. It leaves nothing in it. Yes, more smoke is possible.